Mexican farmers protest NAFTA

MEXICO CITY, Mexico (CNN) -- Hundreds of thousands of farmers clogged central Mexico City Thursday with their slow-moving tractors, protesting the entry of cheap imported corn from the United States and Canada.

On January 1 Mexico repealed all tariffs on corn imported from north of the border as part of a 14-year phaseout under the North American Free Trade Agreement, or NAFTA.

The farmers want the government to renegotiate the 1994 free trade agreement, which removed most trade barriers among Mexico, Canada, and the United States, saying livelihoods are at stake.

"NAFTA is very bad, very bad for Mexican consumers and for Mexican producers," said Victor Quintana, head of Democratic Farmers Front, which organized the protest.

The farmers complain that U.S. and Canadian grains are heavily subsidized and therefore undermine Mexican products.